Work in the third year of the project will continue to assess the applicability of electrohydrodynamic ionization mass spectrometry (EHMS) to the analysis of a variety of non-volatile organic compounds. Preliminary investigations of polymer and surfactant mass spectra will be extended in depth to better assess the possible role of EHMS in analysis of micellar properties. Applicability to other classes of compounds, including antibiotics, will also be investigated. New ion optics will be designed to improve ion collection efficiency. Some source re-design will be undertaken, with the aim of reducing sample consumption rates and facilitating sampling of solvents more volatile than glycerine. Additional source pumping will be installed in an effort to remove some of the volatility constraints presently experienced. Finally, studies will be undertaken to test the feasibility of determination of kinetic parameters for the evaporation of solvent molecules from solvated ions sampled. Information from these studies should aid in the quantitation of EHMS data.